Add full text functions usage in STATS.. WHERE

Author: carlosdelest

x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/lucene/LuceneQueryEvaluator.java

@@ -54,6 +54,7 @@ public record ShardConfig(Query query, IndexSearcher searcher) {}
     private final List<ShardState> perShardState;
 
     protected LuceneQueryEvaluator(BlockFactory blockFactory, ShardConfig[] shards) {
+        assert shards.length > 0 : "LuceneQueryEvaluator expects shard configs";
         this.blockFactory = blockFactory;
         this.shards = shards;
         this.perShardState = new ArrayList<>(Collections.nCopies(shards.length, null));

x-pack/plugin/esql/qa/testFixtures/src/main/resources/kql-function.csv-spec

@@ -189,3 +189,28 @@ book_no:keyword
 7140
 2714
 ;
+
+testKqlInStatsNonPushable
+required_capability: kql_function
+required_capability: full_text_functions_in_stats_where
+
+from books 
+| where length(title) > 40 
+| stats c = count(*) where kql("title:Lord")
+;
+
+c:long
+3
+;
+
+testKqlInStatsPushable
+required_capability: kql_function
+required_capability: full_text_functions_in_stats_where
+
+from books 
+| stats c = count(*) where kql("author:tolkien")
+;
+
+c:long
+22
+;

x-pack/plugin/esql/qa/testFixtures/src/main/resources/match-function.csv-spec

@@ -755,3 +755,29 @@ book_no:keyword
 7140
 2714
 ;
+
+testMatchInStatsNonPushable
+required_capability: match_function
+required_capability: full_text_functions_in_stats_where
+
+from books 
+| where length(title) > 40 
+| stats c = count(*) where match(title, "Lord")
+;
+
+c:long
+3
+;
+
+testMatchInStatsPushable
+required_capability: match_function
+required_capability: full_text_functions_in_stats_where
+
+from books 
+| stats c = count(*) where match(author, "tolkien")
+;
+
+c:long
+22
+;
+

x-pack/plugin/esql/qa/testFixtures/src/main/resources/match-operator.csv-spec

@@ -757,3 +757,29 @@ from semantic_text
 host:keyword | semantic_text_field:text | language_name:keyword | language_code:integer
 "host1"      | live long and prosper    | English               | 1
 ;
+
+
+testMatchInStatsNonPushable
+required_capability: match_operator_colon
+required_capability: full_text_functions_in_stats_where
+
+from books 
+| where length(title) > 40 
+| stats c = count(*) where title:"Lord"
+;
+
+c:long
+3
+;
+
+testMatchInStatsPushable
+required_capability: match_operator_colon
+required_capability: full_text_functions_in_stats_where
+
+from books 
+| stats c = count(*) where author:"tolkien"
+;
+
+c:long
+22
+;

x-pack/plugin/esql/qa/testFixtures/src/main/resources/qstr-function.csv-spec

@@ -210,3 +210,45 @@ book_no:keyword | title:text
 7480            | The Hobbit                                     
 // end::qstr-with-options-result[]
 ;
+
+
+from books 
+| where (match(title, "lord") and ratings > 4.5) or (match(author, "dostoevsky") and length(title) > 50)
+| keep book_no
+;
+ignoreOrder: true
+
+book_no:keyword
+2675
+2924
+4023
+1937
+7140
+2714
+;
+
+testQstrInStatsNonPushable
+required_capability: qstr_function
+required_capability: full_text_functions_in_stats_where
+
+from books 
+| where length(title) > 40 
+| stats c = count(*) where qstr("title:Lord")
+;
+
+c:long
+3
+;
+
+testQstrInStatsPushable
+required_capability: qstr_function
+required_capability: full_text_functions_in_stats_where
+
+from books 
+| stats c = count(*) where qstr("author:tolkien")
+;
+
+c:long
+22
+;
+

x-pack/plugin/esql/src/internalClusterTest/java/org/elasticsearch/xpack/esql/plugin/KqlFunctionIT.java

@@ -66,7 +66,7 @@ public void testKqlQueryWithinEval() {
             """;
 
         var error = expectThrows(VerificationException.class, () -> run(query));
-        assertThat(error.getMessage(), containsString("[KQL] function is only supported in WHERE commands"));
+        assertThat(error.getMessage(), containsString("[KQL] function is only supported in WHERE and STATS ... WHERE commands"));
     }
 
     public void testInvalidKqlQueryEof() {

x-pack/plugin/esql/src/internalClusterTest/java/org/elasticsearch/xpack/esql/plugin/MatchFunctionIT.java

@@ -246,14 +246,35 @@ public void testWhereMatchWithRow() {
         );
     }
 
+    public void testMatchWithStats() {
+        var errorQuery = """
+            FROM test
+            | STATS c = count(*) BY match(content, "fox")
+            """;
+
+        var error = expectThrows(ElasticsearchException.class, () -> run(errorQuery));
+        assertThat(error.getMessage(), containsString("[MATCH] function is only supported in WHERE and STATS ... WHERE commands"));
+
+        var query = """
+            FROM test
+            | STATS c = count(*) WHERE match(content, "fox"), d = count(*) WHERE match(content, "dog")
+            """;
+
+        try (var resp = run(query)) {
+            assertColumnNames(resp.columns(), List.of("c", "d"));
+            assertColumnTypes(resp.columns(), List.of("long", "long"));
+            assertValues(resp.values(), List.of(List.of(2L, 4L)));
+        }
+    }
+
     public void testMatchWithinEval() {
         var query = """
             FROM test
             | EVAL matches_query = match(content, "fox")
             """;
 
         var error = expectThrows(VerificationException.class, () -> run(query));
-        assertThat(error.getMessage(), containsString("[MATCH] function is only supported in WHERE commands"));
+        assertThat(error.getMessage(), containsString("[MATCH] function is only supported in WHERE and STATS ... WHERE commands"));
     }
 
     private void createAndPopulateIndex() {

x-pack/plugin/esql/src/internalClusterTest/java/org/elasticsearch/xpack/esql/plugin/MatchOperatorIT.java

@@ -354,7 +354,7 @@ public void testMatchWithinEval() {
             """;
 
         var error = expectThrows(VerificationException.class, () -> run(query));
-        assertThat(error.getMessage(), containsString("[:] operator is only supported in WHERE commands"));
+        assertThat(error.getMessage(), containsString("[:] operator is only supported in WHERE and STATS ... WHERE commands"));
     }
 
     public void testMatchWithNonTextField() {

x-pack/plugin/esql/src/internalClusterTest/java/org/elasticsearch/xpack/esql/plugin/QueryStringIT.java

@@ -63,7 +63,7 @@ public void testQueryStringWithinEval() {
             """;
 
         var error = expectThrows(VerificationException.class, () -> run(query));
-        assertThat(error.getMessage(), containsString("[QSTR] function is only supported in WHERE commands"));
+        assertThat(error.getMessage(), containsString("[QSTR] function is only supported in WHERE and STATS ... WHERE commands"));
     }
 
     public void testInvalidQueryStringEof() {

x-pack/plugin/esql/src/internalClusterTest/java/org/elasticsearch/xpack/esql/plugin/TermIT.java

@@ -57,7 +57,7 @@ public void testTermWithinEval() {
             """;
 
         var error = expectThrows(VerificationException.class, () -> run(query));
-        assertThat(error.getMessage(), containsString("[Term] function is only supported in WHERE commands"));
+        assertThat(error.getMessage(), containsString("[Term] function is only supported in WHERE and STATS ... WHERE commands"));
     }
 
     public void testMultipleTerm() {